Climate and Vegetation
Chapter 1, Lesson 4
Lesson Objectives
 Identify the factors that affect climate and
vegetation.
 Describe the climate regions of the United
States.
Vocabulary
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Elevation
Natural vegetation
Arid
Tundra
Climate
• Climate – the weather conditions, including temperature,
precipitation, and wind, that occur in an area over a period of
time.
• There are factors that affect the climate of an area:
– Distance from the equator
– Distance from oceans and other large bodies of water
– Elevation (height of the land in relation to the sea level)
• Areas that are closer to the equator (Southern United States)
are warmer than places farther away.
• Areas that are close to water can be warmed by water in the
winter and cooled by the water in the summer.
• Areas with high elevations are cooler than areas with lower
elevations – for every 1,000 feet above sea level, the
temperature drops about 3° F.
Earth and the Sun
• Earth’s orbit around the sun causes changes in seasons –
summer, autumn (fall), winter, and spring.
• Because the earth is tilted on its axis, places get different
amounts of sunlight and heat at different times of the year.
• Some places have four seasons, while other places it is mostly
warm all year or mostly cold all year.
Vegetation
• Weather in the 48 contiguous states generally moves from
west to east.
• Earth is covered with different kinds of natural vegetation, or
plant life that grows naturally in a place.
• The types of vegetation that grows in places depends on
several factors including:
– Soil conditions
– Temperature
– Precipitation
• The amount of precipitation in a place is the single most
important factor affecting where different
kinds of natural vegetation grow.
Vegetation Regions
• Most of the United States can be divided into four main
vegetation regions.
1.
2.
3.
4.
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Forest
Grassland
Desert
Tundra
Forest regions extend across large areas of both the eastern
and western United States.
The larger grassland region in the United States stretches
across the middle of the country.
Only plants that can grown in an arid, or dry, climate can
grow in deserts. These plants include short grasses, low
bushes, and cactuses.
A tundra is a cold, dry region where tress cannot grow.
Tundra regions are covered by snow more than half the year.
Vegetation Regions
Guess the Region
Forest
Grassland
Desert
Tundra